In my talk, I offer six reasons why 2050 is too late (you can access my slides here). Any one of these reasons should be enough to persuade you that the target date be brought forward. Taken together the evidence is overwhelming. As an aide memoire, I condensed the arguments into six images representing six areas of concern:

TINA (there is no alternative to net zero by 2050). It is important to understand that the 2050 target date is NOT a scientific fact and that there are alternatives – they are just politically unpalatable ones.

Poor odds. The IPCC gives us a pathway to 2/3rds odds of keeping below 1.5C; the CCC only gives us better than 50/50.

Feedback loops. There are lots of these. The IPCC does not include feedback loops in its analysis. What it does say is that, if the effects were included, our carbon budget would be reduced by 1/4 (100Gt of a 420Gt budget).

Thermal inertia of oceans. Oceans emit heat, slowly. It causes a time lag – think of the time it takes for a super tanker to make a right turn. System inertia is also not included in the IPCC’s calculations, but 0.6 degrees of warming by 2050 is in the pipeline.

Negative emissions technology (NET). The IPCC reckons that 05-5.0 GtCO2 will need to be removed from the atmosphere come 2050. The biggest CCS plant, the one in Illinois, has so far managed to sequestrate 1.5 MtCO2. Net zero requires NET. Here’s how Kevin Anderson describes it:

Carbon budget. The CCC focuses on nationally determined contributions and % reductions of CO2 from a 1990 baseline. The IPCC warns us that, if met, NDCs will exceed our carbon budget by 113GtCO2. Tim Jackson’s recent analysis suggests that UK emissions will exceed its carbon budget by 2025, and that by 2050 – if the country proceeds along the linear path described by the CCC – the UK will have emitted 5x its carbon budget.

So there you have it. Six reasons why the target of net zero emission by 2050 is a path over a cliff. We mustn’t take that path!

Thankyou Andrew for your very interesting & illuminating talk last night, it was a hot topic in all senses.. I share your concerns about 2050 being too late, I certainly figure that some form of withdrawing carbon from the atmosphere will be needed, but this should be only 5 to 10% of the overall target, we can’t rely on it to allow business as usual. My main problem is in believing that we can get to net-zero in 6 or 11 or even 16 years, but i suppose the main thing is to get down as fast as possible doing the easy stuff first, then we can have a bit of time to do the really difficult last 20-30%, so we’d have a graph like a kid’s slide, starts slowly, build up speed fairly rapidly then slows down at the end before dumping us in the net zero future..
there are several problems in delivering net zero, we have most of the technical know how but we lack business confidence after the debacle of Feed in tariff & the Green Deal, we lack the skillsbase, we lack the capacity to manufacture & install most of the measures we’ll need in anything like the quantities we’ll require & we’ll need to move a bit carefully to ensure there aren’t huge unforseen consequences. These can all be overcome but it requires, even with considerable dedication of time & resources, some time to get us up to speed.